Literature reports indicate that different researchers employ labor intensive and highly diverse techniques for isolation and in vitro generation of antigen presenting cells (APC).
Not only are there various types of APC and protocols for isolating them and activating them in vitro cultures, but also within a given APC type there are variations with regard to isolation and activation procedures. For example, in instance of DC as APC, a variety of methodologies have been reported for the isolation of DC (Macatonia, et al., 1991; Markowicz and Engleman, 1990; Young and Steinman, 1987). Moreover, there appear to be significant differences in the characteristics of the final dendritic cell preparation as indicated by differences in cell surface marker expression, leading to the recent consensus that there exist at least three sub-types of DC (Grabbe, et al., 1995; Thomas and Lipsky, 1994).